Author(s): Shelby Ruesch
Mentor(s): Garrett Cardon
Institution BYU
Introduction: Sensory differences are common in autism and influence several behavioral domains. Unfortunately, behavioral and neural correlates of sensory difficulties remain somewhat elusive, limiting the effectiveness of clinical supports. Forming predictions is central to sensory processing, and has been implicated in autism (i.e., predictive coding). In turn, long-term irregularities in prediction of sensory inputs could lead to an intolerance of uncertainty (IU). Atypical functioning of both sensory cortices and neural processing outside of these areas (i.e., supramodal) likely contribute to such sensory differences. Thus, we propose that irregular functional connectivity in sensory and supramodal brain regions contribute to atypical sensory processing and IU in autistic persons. Thus, we aimed to examine the relationship between behavioral sensory processing, IU, and autistic traits, and the association between these measures and functional connectivity between sensory and supramodal brain regions. We hypothesized that autistic participants would demonstrate significant relationships between sensory processing, IU, and autistic traits, and that these measures would correlate with connectivity between sensory cortices and nodes in a prediction-related brain network (e.g., Siman-Tov et al., 2019). Methods: 30 autistic (27 male; mean age=9.13 years) and 26 nonautistic children (19 male; mean age=9.38) underwent resting-state functional magnetic resonance imaging scans (rs-fMRI). Parents completed several questionnaires: Short Sensory Profile (SSP), Intolerance of Uncertainty Scale (IUS-12), and the Social Responsiveness Scale-2nd Edition(SRS-2). One-way analysis of variance (ANOVA) tested between-groups differences for each behavioral questionnaire. Furthermore, relationships between the behavioral questionnaires were calculated using partial correlations, controlling for age and autistic traits. Finally, between-groups differences were evaluated via multi-voxel pattern analysis (MVPA) in both a combined autistic-neurotypical sample, as well as within each group separately. Results: Behavioral results revealed that autistic children presented with significantly greater sensory atypicalities, IU, and autistic traits, compared to nonautistic children. We also observed significant associations between both behavioral sensory processing and IU and functional connectivity between occipital cortices and the right premotor cortex in the combined sample and within-groups. Distinct, yet overlapping, functional connectivity results were found to be correlated with autistic traits in both groups. Conclusions: Our findings suggest that sensory processing and IU share common brain mechanisms, previously shown to be involved in sensory function, action planning, and prediction. These results may indicate that sensory processing and prediction are linked, both behaviorally and physiologically, along with autistic traits, regardless of diagnosis. These results may provide targets for new and improved supports for autistic people.